The more British expats who register and vote, the more evidence we have to convince the political establishment that there really is a significant body of expats out there who would vote if not already excluded or demotivated by this 15-year-rule.

The fact that expats resident within the EU would be impacted by a Brexit (and for which the government currently seems to have no contingency plan or will not reveal it), also counters one argument of those who resist removing the 15-year-rule i.e. British citizens not living within the UK should not be able to vote in a UK election because they will not be affected by the policies of the government subsequently elected.